Dos FICMs - Contribution code
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Dos FICMs - Contribution code
I was not expecting this to happen, I am getting a contribution code on #4.
Scanned and cleared with TorquePro.
Problem went away ONCE on the drive to getting it emission tested.
Got lucky with that.
Bought hot shot secret. Drove it. Some minor change is throttle response probably VGT getting cleaned up.
Replaced injector - code continues, but the "roughness" did change a little.
Swapped FICM, in the driveway first start no code. Cool!
Drove it around and about five miles into the drive at a light...the elusive contribution code for #4 returned.
I would have thought this contribution code would have been thrown if there was a hard failure in the injector (spool valve hang). I would have thought a Low/High circuit code would be thrown in this case...
So is this an intermittent harness failure??? I guess technically it is possible but want a little confirmation from the Pros here.
Scanned and cleared with TorquePro.
Problem went away ONCE on the drive to getting it emission tested.
Got lucky with that. Bought hot shot secret. Drove it. Some minor change is throttle response probably VGT getting cleaned up.
Replaced injector - code continues, but the "roughness" did change a little.
Swapped FICM, in the driveway first start no code. Cool!
Drove it around and about five miles into the drive at a light...the elusive contribution code for #4 returned.
I would have thought this contribution code would have been thrown if there was a hard failure in the injector (spool valve hang). I would have thought a Low/High circuit code would be thrown in this case...
So is this an intermittent harness failure??? I guess technically it is possible but want a little confirmation from the Pros here.
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What year engine?
Easiest test is to swap injectors with another cylinder and see if the issue remains or follows injector.
Beyond that, inspect all connector pins.
Bubble test that cylinder bank.
Fuel in oil? May have to do an oil drain and do a fuel in oil test.
After that suspect hard part failure, bent pushrod or failing lifter.
Josh
Easiest test is to swap injectors with another cylinder and see if the issue remains or follows injector.
Beyond that, inspect all connector pins.
Bubble test that cylinder bank.
Fuel in oil? May have to do an oil drain and do a fuel in oil test.
After that suspect hard part failure, bent pushrod or failing lifter.
Josh
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Junior User
Joined: Feb 2006
Posts: 77
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What year engine?
Easiest test is to swap injectors with another cylinder and see if the issue remains or follows injector.
Beyond that, inspect all connector pins.
Bubble test that cylinder bank.
Fuel in oil? May have to do an oil drain and do a fuel in oil test.
After that suspect hard part failure, bent pushrod or failing lifter.
Josh
Easiest test is to swap injectors with another cylinder and see if the issue remains or follows injector.
Beyond that, inspect all connector pins.
Bubble test that cylinder bank.
Fuel in oil? May have to do an oil drain and do a fuel in oil test.
After that suspect hard part failure, bent pushrod or failing lifter.
Josh
Injector already swapped, FICM already swapped, no fuel in oil. no oil in coolant.
Lifter failure...didn't think about that. Hmm.
Ill check the connector and go from there.
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I Just started the engine again, it was already warm and it was throwing the contribution code before I shut it off. Upon start everything was smooth. I cleared the codes and re-scanned. All good. I then did my best to wiggle out the harness to force the code to return. Nothing. All is good. So, maybe it is a lifter. Then engines prior life as Im told was in a service truck, the oil in the bottom of the pan was sludge like...so maybe the lifter is acting up because of the oil/hot shot secret? The lifter may be partially stuck down (collapsed) and is working loose? I would get the contribution code on cold start as well.
Still scratching my head on this. The lifter theory seems like it is valid since the contribution code is somewhat intermittent. Could still be a harness if some capacitance or other transient electrical effect is cause by a failing harness. The harness looks great though. No visible damage/wear. I didn't get into look at the socket/pins yet.
I need to look up the bubble test. Im not familiar with that.
Still scratching my head on this. The lifter theory seems like it is valid since the contribution code is somewhat intermittent. Could still be a harness if some capacitance or other transient electrical effect is cause by a failing harness. The harness looks great though. No visible damage/wear. I didn't get into look at the socket/pins yet.
I need to look up the bubble test. Im not familiar with that.
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Ford IDS would help take a lot of guesswork out. Run a contribution test and dynamic compression test.
For hard part failure you would work your way down starting with the rocker arm, pushrod and then lifter.
Josh
For hard part failure you would work your way down starting with the rocker arm, pushrod and then lifter.
Josh
Fleet Mechanic
Joined: Nov 2012
Posts: 1,348
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From: Lakeland, Fl
It's a long shot but the only other links in the chain are the crankshaft and cam sensors, hard to believe they could cause an issue on the same cyl every time but Murphy doesn't play fair.
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